Concrete mixer



Dec. 4, 1962 E.WA1MER ETAL 3,065,919

CONCRETE: MIXER Filed Nw. 4, 1959 A rro A/eys i fed tat s 'i atet Eiibl@ Patented Dec. 4, 1932 tice 3,066,919 CNCRETE MIXER Eberhard aimer, Stockenbergweg 39, Esslingen (Neckar) Liebershronn, and Rudolf Ritter, Rohrhronn, near Filed Nov. 4, 1959, Ser. No. 850,798 Claims priority, application Germany Nov. 12, 1958 11 Ciaims. (Cl. 259-160) The present invention relates to a mixing machine for concrete or similar materials.

lt is an object of the present invention to provide a mixing machine, the individual parts of which may be manufactured and assembled more easily and inexpensively than those of similar mixers as previously designed.

Another object of the invention is to provide a concrete mixer or the like which requires very little space and is low to the ground to facilitate the supply of aggregates to the mixing drum and particularly also to place the center of gravity of the machine at a low level to increase thereby the stability of the machine during its operation and to permit the machine to be easily and safely transported along uneven ground, possibly also on its own mobile undercarriage, without danger of upset.

These Objects are attained according to the invention by providing a low pan-shaped mixing drum which is covered at the top and has in the inside a central cylindrical partition in which a vertical shaft for driving the mixing tools is rotatably mounted in bearings which are thus protected from the contents of the mixer.

According to the invention, the mentioned drive shaft of the mixing tools extends downwardly through the bottom of the mixing drum and is provided below the bottom with a driving gear which is driven by a pinion on a shaft, the bearing of which is mounted on the bottom of the drum, and which extends closely underneath and substantially parallel to the drum to a motor by means of a resilient coupling and a speedreduction gear.

Another important feature of the invention for considerably improving and simplifying the construction of the concrete mixer and rendering its operation more reliable consists in providing the upper end of the drive shaft above the cylindrical partition with a hublikc member on which a cup-shaped cover is mounted which overlaps the upper end of tne cylinder so as to be freely rotatable thereon and prevent the contents of the mixing drum from entering into the cylinder, and which together with the hublilie member also serves to support the mixing tools.

These and other objects, features, and advantages of the present invention will become more apparent from the following detailed descriptlon, particularly when the same is read with reference to the accompanying drawings or one preferred embodiment of the invention, in which- FIGURE l shows, partly in cross section, a side View of a mixing machine according to the invention; while FIGURE 2 shows a front view thereof as seen from the right side of FGURE l.

Referring to the drawings, the mixing machine according to the invention comprises a relatively low, panmixing drum l which is closed at its upper end by a cover il designed so that the highest point of cover 1 is spaced from the upper edge of drum 1 at a distance which is equal to no more than approximately one-half of the height of the drum. The bottom of drum 1 carries a central hollow cylindrical part 2 which extends upwardly therefrom and supports a ring 3 in which a grooved ball bearing i is mounted substantially at the level o the bottom of the drum. The dru-m l is secured on beams 34E and 55 and the cylindrical part 2 rests on the drum 1 on which it is secured as by welding. The cylindrical part 2 further supports near its upper end, by means of a mounting tube d, another ring '7 which supports a second grooved ball bearing These two ball bearings rotatably support a shaft 9, the reduced lower end portion of which extends downwardly from drum 1 and carries a bevel gear lil, while its reduced upper end portion projects from cyilnder 2 .and carries a hub 1l. which is removably secured thereto and is, in turn, rigidly secured to a cup-shaped cover 12 which overlaps mounting tube d so as to be rotatable relative theret0. The gap between cover 12 and cylinder 2 is sealed by a labyrinth packing 13. A washer 14 which is clamped between hub 11 and a shoulder on shaft 9 covers bearing 8 and may slide along ring 7 or overlap the same with a bent-over edge portion to serve as an additional protection of the bearings against the entry of any dirt.

The peripheral wall of the cup-shaped cover 12 has a plurality of apertures, through which arms 15 are insorted which are secured thereto as well as directly to hub l1. The outer ends or" these arms 15' carry plateshaped hat mixing tools 1d arranged on resilient connecting arms 17 which are preferably adjustable on the rigid arms 15.

Bevel gear 1d is enclosed within a housing 13, the peripheral wall or" which also supports a bearing 19 in which a shaft 2d is mounted, which carries on its end within housing l a bevel pinion 21 which is in meshing engagement with bevel gear iii. The other end of shaft 20 carries one member of a resilient clutch or coupling Z3 and connected to the shaft of a gear transmission 24, the housing of which is hanged to an electric motor 25.

This motor 25 is, in turn, secured by an angular bracket 27 to a pair of crossbeams 2S on which a second electric motor 29 is mounted which is connected to a gear transmission which is provided with a brake, not shown. Shaft 31 of transmission 3d carries a hoisting drum 32.

The crossbeams 28 are mounted on longitudinal beams 34, on which the mixing drum 1 is secured which is turther supported by crossbeams 35 which interconnect the longitudinal beams 3d. if the machine is to be mounted in a stationary position, feet 37 may be secured to beams 3f; and 35 at the points of connection ol these beams. However, beams 34 and 35 may also be mounted on a mobile undercarriage either directly or by feet 37 or by any other Suitable connecting means.

The outer ends of the longitudinal beams 34 projecting from mixing drum l support a pair of upwardly inclined rails 38 which are braced on drum 1 by a pair of arms 42 and form the tracks of a hoist on which a hopper 39 may be raised and lowered by means of a rope or cable dit which is secured to hoisting drum 32 and runs over pulleys 445 on a cross beam d5 to hopper 39.

Mixing drum 1 is further provided with a discharging device 47 which is indicated at the left side of FIGURE l by an operating handle 47. A charging funnel 48 is provided on cover 1 at the right side thereof, PEG. l.

By means of a switch, not shown, which may be located at any desired point, motor 25 may thus be operated to drive the mixing tools or plates 16 by means of the transmission 24, the resilient coupling 23, pinion 19 and bevel gear 1li, shaft 9, and arms t5 and 17. Since the speed of motor 25 is reduced considerably by the two sets of reduction gears 2d and 21-1-12, shaft 9 and mixing tools 16 will rotate at a relatively low speed. Due to such steady rotation of the mixing tools as well as due to their design and adiustability on arms 15, they will thoroughly and uniformly mix the materials which are poured from hopper 59 into mixing drum l between cylinder 2 and the outer wall of the drum.

Although our invention has been illustrated and described with reference to the preferred embodiment thereof, we wish to have it understood that it is in no way limited to the details of such embodiment, but is capable bf numerous modications within the scope of the ap- 'pended claims.

Having thus fully disclosed our invention, what we claim is:

1. A mixing machine for concrete and the like comprising a stationary, substantially pan-shaped mixing drum having a central hollow cylindrical member therein projecting upwardly from its bottom, a cover substantially closing the upper end of said drum, a pair of antifriction bearings mounted within said cylindrical member, a substantially vertical shaft mounted in said bearings and extending above said cylindrical member and beiow the level of the bottom of said drum, said cylindrical member having an inner diameter amounting to a multiple of the diameter of said vertical shaft therein, a hub-like member removably secured to the upper end of said shaft above said cylindrical member, a cupshaped cover secured to said hublike member and covering the open upper end of said cylindrical member but so as to be rotatable relative thereto, a plurality of rigid arms extending through the peripheral wall of said cupshaped cover and secured to said wall and also directly to said hublike member, mixing tools within said drum around said cylindrical member, resiliently arranged arms connecting said tools to said rigid arms, a bevel gear mounted on the lower end of said shaft closely underneath said bottom, each of said bearings being adapted to take up loads exerted both in an axial direction of said shaft and transversely thereto, one of said bearings being mounted on the bottom of said cylindrical member and directly adjacent to said bevel gear, and the other bearing being mounted directly adjacent to said hublike member on said cup-shaped cover, means for securing said other bearing to the inner surface of said cylindrical member, a drive shaft extending at a right angle to said first shaft and having a bevel pinion thereon in meshing engagement with said bevel gear, bearing means mounted on Said bottom for rotatably supporting said drive shaft, a motor unit including a speed reduction gear mounted underneath said drum, and a resilient coupling connecting said speed reduction gear to said drive shaft.

2. A mixing machine lfor concrete and the like comprising a base frame, a non-rotary pan-shaped mixing drum secured on the frame, a central hollow cylindrical member projecting upwardly from the bottom of the drum, a vertical shaft mounted in the drum and extending through and above said cylindrical member and through the bottom of the drum, the diameter of the cylindrical member exceeding the diameter of the shaft, a hub-like member secured on Ithe upper end of said shaft above the cylindrical member, a gear wheel mounted on the lower end of the shaft, bearings for the shaft one in the bottom of the drum and another in the top of the drum, the bearing near the upper end of the shaft being supported by an inner wall of the cylindrical member, a driving shaft mounted horizontally from the frame and having motion transfer means on one end thereof to connect with the gear wheel, a motor and transmission gear mounted under the frame and connected to rotate the horizontal shaft, a coupling for a shaft between the transmission gear and the motion transmitting means, a tool carrier mounted on the end of the vertical shaft on a part extending out of the hub-like member and provided with resilient arms, a mixing tool mounted on each of the resilient arms and extending into the drum, the tool carrier extending beyond the cylindrical member around the shaft, said driving shaft being provided at right angles to the vertical shaft and coaxial to the shaft between he transmission gear and the motion transmitting means, a

i cup-shaped cover on the upper endof the vertical shaft and having a plurality of apertures therein through which the tool carriers extend, and bearings provided to support the vertical shaft.

3. A mixing machine for concrete and the like comprising a base frame, a non-rotary pan-shaped mixing drum secured on the frame, a central hollow cylindrical member projecting upwardly from the bottom of the drum, a vertical shaft mounted in the drum and extending through and above said cylindrical member and through the bottom of the drum, the diameter of the cylindrical member exceeding many times the diameter of the shaft, a hub-like member secured on the upper end of said shaft above the cylindrical member, a gear wheel mounted on the lower end of the shaft, bearings for the shaft one in the bottom of the drum and another in the top of the drum, at least one bearing near the upper end of the shaft being supported by an inner wall of the cylindrical member, a driving shaft mounted horizontally from the frame and having motion transfer means on one end thereof to connect with the gear wheel, a motor and transmission gear mounted under the frame and connected to rotate the horizontal shaft, and a tool carrier mounted on the end of the vertical shaft on a part extending out of the hub-like member and provided with arms, and a mixing tool mounted on each of the arms and extending into the drum.

4. A mixing machine as defined in claim 3, further comprising a cover and a funnel-like member projecting from said cover, and hoisting means comprising rails extending in an upward direction and secured at their lower parts to said frame and at their upper parts to said mixing drum, a hopper movable along said rails, and means for moving said hopper between a lower point and a point above said funnel on said cover.

5. A mixing machine as defined in claim 3, further comprising means for securing said mixing tools to said vertical shaft and comprising a hublike member removably secured to the upper end of said shaft above said cylindrical member, a cup-shaped cover secured to said hub-like member and covering the open upper end of said cylindrical member, but so as to be rotatable relative thereto, said last cover also supporting said mixing tools and connecting the same to said hublike member.

6. A mixing machine as defined in claim .3, further comprising a housing completely enclosing said driving gear and pinion, said housing also forming the means for supporting said bearing means of said drive shaft carrying said pinion.

7. A mixing machine according to claim 3, in which a pair of ball bearings are provided one in the bottom of the drum and the other in the top part of the cylindrical member to rotatably support the vertical shaft.

8. A mixing machine as defined in claim 3, further comprising a cover and funnel-like member projecting from said cover, and hoisting means comprising rails extending in an upward direction and secured at their lower parts to said frame and at their upper parts to said mixing drum, a hopper movable along said rails, and means for moving said hopper between a lower point and a point above said funnel on said cover, md further comprising separate driving means for operating said hoisting means, said driving means being mounted intermediate said mixing drum and Said rails at a point substantially vertically above said motor.

9. A mixing machine as dened in claim 3, further comprising a cover and funnel-like member projecting from said cover, and hoisting means comprising rails extending in an upward direction and secured at their lower parts to said frame and at their upper parts to said mixing drum, a hopper movable along said rails, and means for moving said hopper between a lower point and a point above said funnel on said cover, and further comprising separate driving means for operating said hoisting means, said driving means being mounted inter-- mediate said mixing drum and said rails at a point substantially vertically above said motor, and in which said driving means of said hoisting means are also mounted on said common supporting means.

10. A mixing machine as defined in claim 3, further comprising means for securing said mixing tools to said vertical shaft and comprising a hublike member removably secured to the upper end of said shaft above said cylindrical member, a cup-shaped cover secured to said hub-like member and covering the open upper end of said cylindrical member, but so as to be rotatable relative thereto, said last cover also supporting said mixing tools and connecting the same to said hub-like member, and in which said tool carrier comprises a plurality of rigid arms extending through the peripheral wall of said cupshaped cover and secured directly to said hub-like member, at least one resiliently arranged arm adjustably secured at one end to each of said rigid arms, and a mixing blade mounted on the other end of said resiliently arranged arm and adapted to slide substantially along the bottom of said mixing drum.

11. A mixing machine according to claim 3, in which a coupling is provided for the driving shaft mounted between the transmission gear and the vertical shaft and which is elastic.

References Cited in the tile of this patent UNITED STATES PATENTS 1,184,339 Fowler May 23, 1916 1,363,560 Browne Dec. 28, 1920 2,049,866 Rapp et al Aug. 4, 1936 2,284,765 Pierce June 2, 1942 2,306,422 Beardsley et al. Dec. 29, 1942 2,717,147 Fejmert et al. Sept. 6, 1955 2,727,696 Horth Dec. 20, 1955 FOREIGN PATENTS 1,014,756 France Mar. 17, 19150 1,222,527 France Dec. 11, 1958 675,393 Great Britain July 9, 1952 OTHER REFERENCES Barnett, E. de Barry, Explosives, TP270B3, Bailliere, Tindall & Cox, 8, Henrietta St., Covent Garden, England, 1919.

Helene, Maxime, La Poudre A Cannon TP 272H474, Librairie Hachette et Cie, Paris, 1878. 

